Field of the Invention
The present invention relates to a processing apparatus, a processing method, and a device manufacturing method.
Description of the Related Art
Conventionally, a semiconductor exposure apparatus used for the manufacture of a semiconductor element has, for example, a wafer transfer hand that supplies a wafer with a wafer stage and collects the wafer, a pre-alignment stage, and a wafer stage transfer robot. In the pre-alignment stage, before the wafer is moved to the wafer stage, the alignment of the wafer is performed by using a notch or an orientation flat. The wafer stage transfer robot holds the wafer by using vacuum pressure and transfers it. Japanese Patent Laid-Open No. 2008-251754 discloses a pin that holds the wafer above the wafer stage and a pin drive mechanism used when the wafer is supplied and collected by the wafer transfer hand.
In recent years, the manufacture of micro electro mechanical systems (MEMS) has been performed by applying the manufacturing technique of such a semiconductor integrated circuit. “MEMS” refer to devices in which a machine element component, a sensor, an actuator, an electronic circuit, and the like are integrated on a silicon substrate, a glass substrate, an organic material, or the like.
In this connection, unlike conventional semiconductor devices, in the MEMS, mechanical processing is usually performed on a semiconductor member as a target, and, for example, there are cases in which through holes are formed from the surface to the back of the wafer. In a case where the technique disclosed in Japanese Patent Laid-Open No. 2008-251754 is used for the manufacture of the MEMS, there are cases in which an attracting force cannot be sufficiently obtained if the through holes and the attracting units are overlapped for a wafer in which through holes have been formed. When the attracting force cannot be sufficiently obtained, the apparatus may stop due to attraction abnormalities. Additionally, a vacuum source pressure may vary due to the leakage of attracting air, and the attraction by another attraction holding mechanism connected to the identical vacuum source pressure may be decreased. When the apparatus stops, throughput of the apparatus decreases, and when the attracting force decreases, it will affect the reliability of the apparatus.